The present invention relates to a manhole cover locking bolt.
By way of background, in the past manhole covers of certain types were secured to their associated frames by means of bolts having conventional heads which could be removed by readily available wrenches. Thus, unauthorized access was available to cable-carrying tunnels by personnel who wished to install additional cables along the route of existing cables. Unauthorized access was also available to sewers for improper dumping of toxic wastes.